Art of silk manufacture



Patented Mar. 14,1933

' UNITED STATES WILLIAM H. FURNESS, on NATIONAL PARK, E JEnsEY,'Ass1 NoR, BY MESNE AS; SIGNMENTS, T FURNESS CORPORATION, or PHILADELZPHIA, PENNSY A IA, A

CORPORATION OF NEW JERSEY" ART or SILK MANUFACTURE No Drawing.

The deposition of copper which occurs 'when employing weak solutions results in a number of disadvantages, among which the following may be mentioned: the thread cannot be wound upon the spool or bobbin without sticking thereto and without sticking of the strands of thread, the thread is opaque, and the finished or conditioned thread is fuzzy.

If the solution could be weak, a great saving in expense would result, due to the relatively small amount of caustic soda carried by the thread and to the saving in the amount of acid required to remove the caustic soda and the copper hydrate; and it is the primary purpose of the present invention to effect this saving and to permit of the employment of a relatively weak caustic solution without encountering the difiiculties hereinabove noted.

Other advantages of the invention will appear hereinafter.

In carrying out my invention I reduce the percentage of caustice soda in the solution and employ an additional substance or substances which are unaffected by the caustic soda and which will have the effect of keeping the copper soluble. As one such substance or material, I propose glycerine and in the preferred form of my invention I employ a solution containing about 1% glycerine, 10% caustic and the balance Water.

Application filed December 12, 1927. Serial No. 239,615.

As the filaments are spun into this solution and the thread is formed, some of the copper and ammonia enter the bath and apparently the glycerine unites with the copper 'hydroxide, caustic soda and ammonia in a soluble,

form. In any event, vI find that the copper does not deposit on the thread and guides,

and the thread is clear and does not adhere to the spool or bobbin nor do the strands of wf: the thread being laid upon the spool adhere.

to one another. Consequently, "the above mentioned solution is especially useful in the manufacture of fine filament silk, that is to say, a product having filaments of about two 1 and one-half denier or less and also of fine counts (denier of the thread). Heretofore, great difiiculty has been encountered in-the production of such fine filament rayon, primarily because of breakage of the'fine fila- I ments in the spinning. The product has been ob ectionably fuzzy, due to the presence of "broken filaments. Apparently the glycerine ments into the thread without breakage of the filaments. Because of this the thread, after hasbeen decopped, washed and dried, is free from fuzz. Furthermore, the glycerine seems to reduce the amount of oxidation which occurs in the thread in the presence of air and caustic soda and a spool can stand for a great many hours without anydeterioration.

In addition to thefo'regoing advantages, I find that the costs are still further reduced by virtue of the fact that I am. enabled to obtain substantially complete recovery.

Thus, when the bath becomes .objectionably I laden with copper and ammonia, I remove the ammonia by applying a heat, after which- While I have specifically mentioned glyc- (Wine for the purposes of my invention, it is to be understood that I am not limited to the employment thereof.

' What I claim is I The method of preventing precipitation of copper duringvprecipitation of suproammonium silk thread, which includes spinning the thread in a precipitating bath containing about 1% of glycerin and about of caustic sodar In testimpny whereof -I have hefeunto V i a signed my name. 

